﻿//-----------------------------------------------------------------------
// <copyright company="www.3WayWebdesign.de">
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// </copyright>
//
// <author>Michael Morbach</author>
// <email>Michael@3waywebdesign.de</email>
// <web>http://www.3waywebdesign.de</web>
//-----------------------------------------------------------------------

using System;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Data;
using System.Windows.Media;
using Tww.Wpf.Controls.Controls.Shared.Helper;

namespace Tww.Wpf.Controls.Converters
{
    public class BackgroundToForegroundConverter : IValueConverter, IMultiValueConverter
    {
        #region  - Felder (privat) -

        private static BackgroundToForegroundConverter _instance;

        #endregion

        // Explicit static constructor to tell C# compiler
        // not to mark type as beforefieldinit

        #region  - Konstruktoren -

        static BackgroundToForegroundConverter()
        {
        }

        #endregion

        #region  - Konstruktoren -

        private BackgroundToForegroundConverter()
        {
        }

        #endregion

        #region  - Indexer und Eigenschaften (öffentlich) -

        public static BackgroundToForegroundConverter Instance
        {
            get { return _instance ?? (_instance = new BackgroundToForegroundConverter()); }
        }

        #endregion

        #region  - IMultiValueConverter Members -

        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            Brush bgBrush = values.Length > 0 ? values[0] as Brush : null;
            Brush titleBrush = values.Length > 1 ? values[1] as Brush : null;
            if (titleBrush != null)
            {
                return titleBrush;
            }
            return Convert(bgBrush, targetType, parameter, culture);
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            return targetTypes.Select(t => DependencyProperty.UnsetValue).ToArray();
        }

        #endregion

        #region  - IValueConverter Members -

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var backgroundBrush = value as SolidColorBrush;
            if (backgroundBrush != null)
            {
                Color idealForegroundColor = ColorHelper.GetIdealTextColorByBackgroundColor(backgroundBrush.Color);
                var foreGroundBrush = new SolidColorBrush(idealForegroundColor);
                foreGroundBrush.Freeze();
                return foreGroundBrush;
            }
            return Brushes.White;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return DependencyProperty.UnsetValue;
        }

        #endregion
    }
}